1. Rút gọn biểu thức sau:
a) 3ab . ( a + b ) – ab . { 2. ( 3 – a ) – [4b – 5 . ( 3 – 2b ) ] }
giúp mình vs nha mấy bạn yêu !!!!!!!!!!!
1. Rút gọn biểu thức sau: a) 3ab . ( a + b ) – ab . { 2. ( 3 – a ) – [4b – 5 . ( 3 – 2b ) ] } giúp mình vs nha mấy bạn yêu !!!!!!!!!!!
By Everleigh
$3ab . ( a + b ) – ab . { 2. ( 3 – a ) – [4b – 5 . ( 3 – 2b ) ] }$
$=3a^2b+3ab^2-ab[6-2a-(4b-15+10b)]$
$=3a^2b+3ab^2-ab[6-2a-(-15+14b)]$
$= 3a^2b+3ab^2-ab(6-2a+15-14b)$
$= 3a^2b+3ab^2-ab(21-16b)$
$= 3a^2b+3ab^2-21ab+16ab^2$
$= 3a^2b-21ab+19ab^2$
cho mik ctlhn nha
1.a, 3ab.(a+b)-ab.{2.(3-a)-[4b-5.(3-2b)]}
= 3a²b+3ab²-ab.{6-2a-[4b-15+10b]}
= 3a²b+3ab²-ab.(6-2a-4b+15-10b)
= 3a²b+3ab²-6ab+2a²b+4ab²-15ab+10ab²
= 5a²b+17ab²-21ab
= ab(5a+17b-21)